/**

 * $Id$

 * 

 * SH4->x86 translation module

 *

 * Copyright (c) 2005 Nathan Keynes.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 */

#include "sh4/xltcache.h"

#include "dream.h"

#include "mem.h"

/** Maximum size of a translated instruction, in bytes. This includes potentially

 * writing the entire epilogue

 */

#define MAX_INSTRUCTION_SIZE 256

/** Maximum size of the translation epilogue (current real size is 116 bytes, so

 * allows a little room

 */

#define EPILOGUE_SIZE 128

/** Maximum number of recovery records for a translated block (2048 based on

 * 1 record per SH4 instruction in a 4K page).

 */

#define MAX_RECOVERY_SIZE 2048

/**

 * Translation flag - exit the current block but continue (eg exception handling)

 */

#define XLAT_EXIT_CONTINUE 1

/**

 * Translation flag - exit the current block and halt immediately (eg fatal error)

 */

#define XLAT_EXIT_HALT 2

/**

 * Translation flag - exit the current block and halt immediately for a system

 * breakpoint.

 */

#define XLAT_EXIT_BREAKPOINT 3

/**

 * Translation flag - exit the current block and continue after performing a full

 * system reset (dreamcast_reset())

 */

#define XLAT_EXIT_SYSRESET 4

/**

 * Translation flag - exit the current block and continue after the next IRQ.

 */

#define XLAT_EXIT_SLEEP 5

/**

 */

uint32_t sh4_xlat_run_slice( uint32_t nanosecs );

/**

 * Return true if translated code is currently running

 */

gboolean sh4_xlat_is_running();

/**

 * Initialize the translation engine (if required). Note xlat cache

 * must already be initialized.

 */

void sh4_xlat_init();

/**

 * Translate the specified block of code starting from the specified start

 * address until the first branch/jump instruction.

 */

void *sh4_translate_basic_block( sh4addr_t start );

/**

 * Add a recovery record for the current code generation position, with the

 * specified instruction count

 */

void sh4_translate_add_recovery( uint32_t icount );

extern uint8_t *xlat_output;

extern struct xlat_recovery_record xlat_recovery[MAX_RECOVERY_SIZE];

extern xlat_cache_block_t xlat_current_block;

extern uint32_t xlat_recovery_posn;

/******************************************************************************

 * Code generation - these methods must be provided by the

 * actual code gen (eg sh4x86.c) 

 ******************************************************************************/

#define TARGET_X86 1

void sh4_translate_init( void );

void sh4_translate_begin_block( sh4addr_t pc );

uint32_t sh4_translate_instruction( sh4addr_t pc );

void sh4_translate_end_block( sh4addr_t pc );

uint32_t sh4_translate_end_block_size();

void sh4_translate_emit_breakpoint( sh4vma_t pc );

typedef void (*unwind_thunk_t)(void);

/**

 * From within the translator, (typically called from MMU exception handling routines)

 * immediately exit the current translation block (performing cleanup as necessary) and

 * return to sh4_xlat_run_slice(). Effectively a fast longjmp w/ xlat recovery.

 *

 * Note: The correct working of this method depends on the translator anticipating the

 * exception and generating the appropriate recovery block(s) - currently this means 

 * that it should ONLY be called from within the context of a memory read or write.

 *

 * @param is_completion If TRUE, exit after completing the current instruction (effectively),

 *   otherwise abort the current instruction with no effect. 

 * @param thunk A function to execute after perform xlat recovery, but before returning

 * to run_slice. If NULL, control returns directly.

 * @return This method never returns. 

 */

void sh4_translate_unwind_stack( gboolean is_completion, unwind_thunk_t thunk );

/**

 * From within the translator, immediately exit the current translation block with

 * the specified exit code (one of the XLAT_EXIT_* values).

 */

void sh4_translate_exit( int exit_code );

/**

 * From within the translator, exit the current block at the end of the 

 * current instruction, flush the translation cache (completely) and return

 * control to sh4_xlat_run_slice.

 */

void sh4_translate_flush_cache( void );

/**

 * Support function called from the translator when a breakpoint is hit.

 * Either returns immediately (to skip the breakpoint), or aborts the current

 * cycle and never returns.

 */

void sh4_translate_breakpoint_hit( sh4vma_t pc );